Scott Killton, 32, of Naples, hit a small stump on a trail near 575 Hancock Pond Road around 10 a.m. and landed on a 1-inch stick, which impaled his lower back and abdomen, according to the Maine Warden Service.

Killton was treated at the scene and flown by helicopter to Maine Medical Center in Portland.

Killton was riding his Yamaha dirt bike with four other friends. All riders had full safety gear, including helmets, wardens said.